Relationship Between Skin Scales and the Main Flow Field Around the Shortfin Mako Shark Isurus oxyrinchus
The aim of this study was to reveal potential relationship between the main flow field around a shortfin mako shark and the surface morphology of shark skin. Firstly, a numerical simulation using the large eddy simulation (LES) method was conducted to obtain the main flow field around a smooth shark...
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| Format: | Article |
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Frontiers Media S.A.
2022-04-01
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| Series: | Frontiers in Bioengineering and Biotechnology |
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| Online Access: | https://www.frontiersin.org/articles/10.3389/fbioe.2022.742437/full |
| _version_ | 1818523890502074368 |
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| author | Chengchun Zhang Chengchun Zhang Chengchun Zhang Meihong Gao Guangyuan Liu Yihua Zheng Chen Xue Chun Shen Chun Shen |
| author_facet | Chengchun Zhang Chengchun Zhang Chengchun Zhang Meihong Gao Guangyuan Liu Yihua Zheng Chen Xue Chun Shen Chun Shen |
| author_sort | Chengchun Zhang |
| collection | DOAJ |
| description | The aim of this study was to reveal potential relationship between the main flow field around a shortfin mako shark and the surface morphology of shark skin. Firstly, a numerical simulation using the large eddy simulation (LES) method was conducted to obtain the main flow field around a smooth shark model. Then, the surface morphology characteristics of a shark (Isurus oxyrinchus) at different positions were characterized by scanning electron microscope (SEM), which showed that the morphology, riblet size, and density of scales at different positions on the shark were significantly different. At positions where the surfaces face into the water flow direction (i.e., nose and leading edge of fins), the scales were flat and round, with a lower density, and the pressure or wall shear stress (WSS) was greater. Scales with three longitudinal riblets ending in three tips were found on the middle and trailing edges of the first dorsal fin and caudal fin, where water flow states progress from transitional to turbulent. The ranges of the ratio of riblet depth to spacing (RD/RS) in the anterior zone, middle zone and posterior zone of the shark were 0.05–0.17, 0.08–0.23, and 0.32–0.33, respectively. The riblet angle generally followed the flow direction, but it varied across different areas of the body. The turbulence intensity increased gradually across the first dorsal fin, pectoral fin, caudal fin, and the shark body overall. In summary, it was found that the microstructure riblets on the shark skin surface, generally thought to be drag reduction structures, were only located in transitional and turbulent regions at the middle and trailing edge of the shark body and fin surfaces, and there were almost no microstructural grooves in the laminar flow regions along the leading edge. These findings can provide design guidance for engineering applications of bionic riblet surfaces. Riblets placed in transitional and fully turbulent regions can be used to effectively reduce drag. The riblet direction should be consistent with the direction of flow. |
| first_indexed | 2024-12-11T05:50:19Z |
| format | Article |
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| institution | Directory Open Access Journal |
| issn | 2296-4185 |
| language | English |
| last_indexed | 2024-12-11T05:50:19Z |
| publishDate | 2022-04-01 |
| publisher | Frontiers Media S.A. |
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| series | Frontiers in Bioengineering and Biotechnology |
| spelling | doaj.art-7fb69ad56dfd4b1b8237405139e830ea2022-12-22T01:18:50ZengFrontiers Media S.A.Frontiers in Bioengineering and Biotechnology2296-41852022-04-011010.3389/fbioe.2022.742437742437Relationship Between Skin Scales and the Main Flow Field Around the Shortfin Mako Shark Isurus oxyrinchusChengchun Zhang0Chengchun Zhang1Chengchun Zhang2Meihong Gao3Guangyuan Liu4Yihua Zheng5Chen Xue6Chun Shen7Chun Shen8Key Laboratory of Bionic Engineering (Ministry of Education), Jilin University, Changchun, ChinaState Key Laboratory of Automotive Simulation and Control, Jilin University, Changchun, ChinaWeihai Institute of Bionics, Jilin University, Weihai, ChinaKey Laboratory of Bionic Engineering (Ministry of Education), Jilin University, Changchun, ChinaChina Aerodynamics Research and Development Center, Mianyang, ChinaAdvanced Materials Industry Institute of Guangxi Academy of Science, Nanning, ChinaSchool of Energy Science and Engineering, Harbin Institute of Technology, Harbin, ChinaKey Laboratory of Bionic Engineering (Ministry of Education), Jilin University, Changchun, ChinaState Key Laboratory of Automotive Simulation and Control, Jilin University, Changchun, ChinaThe aim of this study was to reveal potential relationship between the main flow field around a shortfin mako shark and the surface morphology of shark skin. Firstly, a numerical simulation using the large eddy simulation (LES) method was conducted to obtain the main flow field around a smooth shark model. Then, the surface morphology characteristics of a shark (Isurus oxyrinchus) at different positions were characterized by scanning electron microscope (SEM), which showed that the morphology, riblet size, and density of scales at different positions on the shark were significantly different. At positions where the surfaces face into the water flow direction (i.e., nose and leading edge of fins), the scales were flat and round, with a lower density, and the pressure or wall shear stress (WSS) was greater. Scales with three longitudinal riblets ending in three tips were found on the middle and trailing edges of the first dorsal fin and caudal fin, where water flow states progress from transitional to turbulent. The ranges of the ratio of riblet depth to spacing (RD/RS) in the anterior zone, middle zone and posterior zone of the shark were 0.05–0.17, 0.08–0.23, and 0.32–0.33, respectively. The riblet angle generally followed the flow direction, but it varied across different areas of the body. The turbulence intensity increased gradually across the first dorsal fin, pectoral fin, caudal fin, and the shark body overall. In summary, it was found that the microstructure riblets on the shark skin surface, generally thought to be drag reduction structures, were only located in transitional and turbulent regions at the middle and trailing edge of the shark body and fin surfaces, and there were almost no microstructural grooves in the laminar flow regions along the leading edge. These findings can provide design guidance for engineering applications of bionic riblet surfaces. Riblets placed in transitional and fully turbulent regions can be used to effectively reduce drag. The riblet direction should be consistent with the direction of flow.https://www.frontiersin.org/articles/10.3389/fbioe.2022.742437/fullbiomimeticssharkmain flow fieldscalerelationship |
| spellingShingle | Chengchun Zhang Chengchun Zhang Chengchun Zhang Meihong Gao Guangyuan Liu Yihua Zheng Chen Xue Chun Shen Chun Shen Relationship Between Skin Scales and the Main Flow Field Around the Shortfin Mako Shark Isurus oxyrinchus Frontiers in Bioengineering and Biotechnology biomimetics shark main flow field scale relationship |
| title | Relationship Between Skin Scales and the Main Flow Field Around the Shortfin Mako Shark Isurus oxyrinchus |
| title_full | Relationship Between Skin Scales and the Main Flow Field Around the Shortfin Mako Shark Isurus oxyrinchus |
| title_fullStr | Relationship Between Skin Scales and the Main Flow Field Around the Shortfin Mako Shark Isurus oxyrinchus |
| title_full_unstemmed | Relationship Between Skin Scales and the Main Flow Field Around the Shortfin Mako Shark Isurus oxyrinchus |
| title_short | Relationship Between Skin Scales and the Main Flow Field Around the Shortfin Mako Shark Isurus oxyrinchus |
| title_sort | relationship between skin scales and the main flow field around the shortfin mako shark isurus oxyrinchus |
| topic | biomimetics shark main flow field scale relationship |
| url | https://www.frontiersin.org/articles/10.3389/fbioe.2022.742437/full |
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